From patchwork Wed Jul 20 16:49:14 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avi Kivity X-Patchwork-Id: 105980 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 89F35B6F77 for ; Thu, 21 Jul 2011 16:42:03 +1000 (EST) Received: from localhost ([::1]:50531 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qje1K-00025h-9F for incoming@patchwork.ozlabs.org; Wed, 20 Jul 2011 17:09:30 -0400 Received: from eggs.gnu.org ([140.186.70.92]:55240) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjZz8-00034B-Sb for qemu-devel@nongnu.org; Wed, 20 Jul 2011 12:51:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QjZys-0004tg-Dt for qemu-devel@nongnu.org; Wed, 20 Jul 2011 12:50:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35981) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QjZyr-0004tI-Jk for qemu-devel@nongnu.org; Wed, 20 Jul 2011 12:50:42 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p6KGoepe022620 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 20 Jul 2011 12:50:40 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p6KGodjH030725; Wed, 20 Jul 2011 12:50:40 -0400 Received: from s01.tlv.redhat.com (s01.tlv.redhat.com [10.35.255.8]) by cleopatra.tlv.redhat.com (Postfix) with ESMTP id ED03E250B36; Wed, 20 Jul 2011 19:50:38 +0300 (IDT) From: Avi Kivity To: qemu-devel@nongnu.org Date: Wed, 20 Jul 2011 19:49:14 +0300 Message-Id: <1311180636-17012-5-git-send-email-avi@redhat.com> In-Reply-To: <1311180636-17012-1-git-send-email-avi@redhat.com> References: <1311180636-17012-1-git-send-email-avi@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: kvm@vger.kernel.org Subject: [Qemu-devel] [RFC v5 04/86] memory: merge adjacent segments of a single memory region X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Simple implementations of memory routers, for example the Cirrus VGA memory banks or the 440FX PAM registers can generate adjacent memory regions which are contiguous. Detect these and merge them; this saves kvm memory slots and shortens lookup times. Signed-off-by: Avi Kivity --- memory.c | 22 ++++++++++++++++++++++ 1 files changed, 22 insertions(+), 0 deletions(-) diff --git a/memory.c b/memory.c index a569666..339bea3 100644 --- a/memory.c +++ b/memory.c @@ -122,6 +122,27 @@ static void flatview_destroy(FlatView *view) qemu_free(view->ranges); } +/* Attempt to simplify a view by merging ajacent ranges */ +static void flatview_simplify(FlatView *view) +{ + unsigned i; + FlatRange *r1, *r2; + + for (i = 0; i + 1 < view->nr; ++i) { + r1 = &view->ranges[i]; + r2 = &view->ranges[i+1]; + if (addrrange_end(r1->addr) == r2->addr.start + && r1->mr == r2->mr + && r1->offset_in_region + r1->addr.size == r2->offset_in_region + && r1->dirty_log_mask == r2->dirty_log_mask) { + r1->addr.size += r2->addr.size; + memmove(r2, r2 + 1, (view->nr - (i + 2)) * sizeof(*r2)); + --view->nr; + --i; + } + } +} + /* Render a memory region into the global view. Ranges in @view obscure * ranges in @mr. */ @@ -209,6 +230,7 @@ static FlatView generate_memory_topology(MemoryRegion *mr) flatview_init(&view); render_memory_region(&view, mr, 0, addrrange_make(0, UINT64_MAX)); + flatview_simplify(&view); return view; }